Influence of Light on Germination of Pinus palustris Seeds

Red light with a wavelength of 660 nm promotes germination of longleaf pine (Pinus palustris Mill.) seeds, and far-red light (730 nm) inhibits germination. The promotion-inhibition process is repeatedly reversible, indicating that germination is controlled by the photoreversible reaction of phytochrome. Response varied greatly between single-tree lots and was dependent on the length of time seeds were imbibed at 5°C. Dry seeds did not respond to light treatments when they were subsequently imbibed and tested in darkness. Stratification for 28 days essentially removed the light requirements for germination.